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Howlett" , Uladzislau Rezki , Jiri Slaby , "Rafael J. Wysocki" Cc: greybus-dev@lists.linaro.org, linux-serial@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, driver-core@lists.linux.dev, Markus Probst X-Developer-Signature: v=1; a=openpgp-sha256; l=6268; i=markus.probst@posteo.de; h=from:subject:message-id; bh=PKa3wcoCH2wHJkmcs/mXYYpls+IcD7g7mkDOeKBFHEI=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBq9fea6DB54ww5B9+/Z8v/ugnQKgb7UdH35K6r1 JCpHjrAJIOJAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCavX3mhsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQNHYf+OetQ9Ihvg//Wt8RJ8ULVpkjtTrdl/SNtQsylHQPO2y yAaxUNPTGo/uP1yQ37LTjrSLN+QphMqq0jZiMDfgPQrlYJkydU3KxoDcbT5rNQlInQbMDgRbekH Rf83RowBsIkpmaKip/TyGC+JuKuYUBJXP7znm2ZYVCJXWNKJJoW77V1+M+PfKvKEKRCtCHLDXQP VwbcQDOQIhh8Q5tEv33gy/A6dxfE1BXOFwt1qgWFP538cLN0LEuaESMSFA2/Gw8ydIuMq2vJ/R7 jW/pPVW1397lYXNmvQk1qdTebI/Id/A/mkymPK4gkv8hx+0ZFUAqkA6Rw+PaQWxHbmvOdgY6T7v oUVVvAZNJ09PmxhOwLHNTzP9X+Q3XHmv5PC5oIo0n4Kiio1RmfKmW/236I+QPfPbLZVr574XOs+ u5e4GMtxvmN6+KPypDTOlkVuDoXkT8ofLYtD7MjX2v71hoqt9fSMLln//JjtjlaALG3gCH8TcmV tcvltOzv7x9Z6Dn7NMu1YG7/UOxc6/0l4ovkTA0PNwsH2Tvumn1AQOFM/f1UPYPH7okxj1bYp4c OdA4keqERzAI0XDf9omcKKsoDzfxRu5qeRqHrAZ7p4LK1D8ehKtSVcv4dpp2iQTxxSUq9J7W65V KklMWJ+27a7Cl6rtk6+kVYjg3wi/IR28SGpN4oGxO9m4Avuf56xA= X-Developer-Key: i=markus.probst@posteo.de; a=openpgp; fpr=827418C4F4AC58E77230C47334761FF8E7AD43D2 Autocrypt: addr=markus.probst@posteo.de; prefer-encrypt=mutual; keydata=xsFNBGiDvXgBEADAXUceKafpl46S35UmDh2wRvvx+UfZbcTjeQOlSwKP7YVJ4JOZrVs93qReNLkO WguIqPBxR9blQ4nyYrqSCV+MMw/3ifyXIm6Pw2YRUDg+WTEOjTixRCoWDgUj1nOsvJ9tVAm76Ww+ /pAnepVRafMID0rqEfD9oGv1YrfpeFJhyE2zUw3SyyNLIKWD6QeLRhKQRbSnsXhGLFBXCqt9k5JA RhgQof9zvztcCVlT5KVvuyfC4H+HzeGmu9201BVyihJwKdcKPq+n/aY5FUVxNTgtI9f8wIbmfAja oT1pjXSp+dszakA98fhONM98pOq723o/1ZGMZukyXFfsDGtA3BB79HoopHKujLGWAGskzClwTjRQ xBqxh/U/lL1pc+0xPWikTNCmtziCOvv0KA0arDOMQlyFvImzX6oGVgE4ksKQYbMZ3Ikw6L1Rv1J+ FvN0aNwOKgL2ztBRYscUGcQvA0Zo1fGCAn/BLEJvQYShWKeKqjyncVGoXFsz2AcuFKe1pwETSsN6 OZncjy32e4ktgs07cWBfx0v62b8md36jau+B6RVnnodaA8++oXl3FRwiEW8XfXWIjy4umIv93tb8 8ekYsfOfWkTSewZYXGoqe4RtK80ulMHb/dh2FZQIFyRdN4HOmB4FYO5sEYFr9YjHLmDkrUgNodJC XCeMe4BO4iaxUQARAQABzRdtYXJrdXMucHJvYnN0QHBvc3Rlby5kZcLBkQQTAQgAOxYhBIJ0GMT0 rFjncjDEczR2H/jnrUPSBQJog714AhsDBQsJCAcCAiICBhUKCQgLAgQWAgMBAh4HAheAAAoJEDR2 H/jnrUPSgdkQAISaTk2D345ehXEkn5z2yUEjaVjHIE7ziqRaOgn/QanCgeTUinIv6L6QXUFvvIfH 1OLPwQ1hfvEg9NnNLyFezWSy6jvoVBTIPqicD/r3FkithnQ1IDkdSjrarPMxJkvuh3l7XZHo49GV HQ8i5zh5w4YISrcEtE99lJisvni2Jqx7we5tey9voQFDyM8jxlSWv3pmoUTCtBkX/eKHJXosgsuS B4TGDCVPOjla/emI5c9MhMG7O4WEEmoSdPbmraPw66YZD6uLyhV4DPHbiDWRzXWnClHSyjB9rky9 lausFxogvu4l9H+KDsXIadNDWdLdu1/enS/wDd9zh5S78rY2jeXaG4mnf4seEKamZ7KQ6FIHrcyP ezdDzssPQcTQcGRMQzCn6wP3tlGk7rsfmyHMlFqdRoNNv+ZER/OkmZFPW655zRfbMi0vtrqK2Awm 9ggobb1oktfd9PPNXMUY+DNVlgR2G7jLnenSoQausLUm0pHoNE8TWFv851Y6SOYnvn488sP1Tki5 F3rKwclawQFHUXTCQw+QSh9ay8xgnNZfH+u9NY7w3gPoeKBOAFcBc2BtzcgekeWS8qgEmm2/oNFV G0ivPQbRx8FjRKbuF7g3YhgNZZ0ac8FneuUtJ2PkSIFTZhaAiC0utvxk0ndmWFiW4acEkMZGrLaM L2zWNjrqwsD2zsFNBGiDvXgBEADCXQy1n7wjRxG12DOVADawjghKcG+5LtEf31WftHKLFbp/HArj BhkT6mj+CCI1ClqY+FYU5CK/s0ScMfLxRGLZ0Ktzawb78vOgBVFT3yB1yWBTewsAXdqNqRooaUNo 8cG/NNJLjhccH/7PO/FWX5qftOVUJ/AIsAhKQJ18Tc8Ik73v427EDxuKb9mTAnYQFA3Ev3hAiVbO 6Rv39amVOfJ8sqwiSUGidj2Fctg2aB5JbeMln0KCUbTD1LhEFepeKypfofAXQbGwaCjAhmkWy/q3 IT1mUrPxOngbxdRoOx1tGUC0HCMUW1sFaJgQPMmDcR0JGPOpgsKnitsSnN7ShcCr1buel7vLnUMD +TAZ5opdoF6HjAvAnBQaijtK6minkrM0seNXnCg0KkV8xhMNa6zCs1rq4GgjNLJue2EmuyHooHA4 7JMoLVHcxVeuNTp6K2+XRx0Pk4e2Lj8IVy9yEYyrywEOC5XRW37KJjsiOAsumi1rkvM7QREWgUDe Xs0+RpxI3QrrANh71fLMRo7LKRF3Gvw13NVCCC9ea20P4PwhgWKStkwO2NO+YJsAoS1QycMi/vKu 0EHhknYXamaSV50oZzHKmX56vEeJHTcngrM8R1SwJCYopCx9gkz90bTVYlitJa5hloWTYeMD7FNj Y6jfVSzgM/K4gMgUNDW/PPGeMwARAQABwsF2BBgBCAAgFiEEgnQYxPSsWOdyMMRzNHYf+OetQ9IF AmiDvXgCGwwACgkQNHYf+OetQ9LHDBAAhk+ab8+WrbS/b1/gYW3q1KDiXU719nCtfkUVXKidW5Ec Idlr5HGt8ilLoxSWT2Zi368iHCXS0WenGgPwlv8ifvB7TOZiiTDZROZkXjEBmU4nYjJ7GymawpWv oQwjMsPuq6ysbzWtOZ7eILx7cI0FjQeJ/Q2baRJub0uAZNwBOxCkAS6lpk5Fntd2u8CWmDQo4SYp xeuQ+pwkp0yEP30RhN2BO2DXiBEGSZSYh+ioGbCHQPIV3iVj0h6lcCPOqopZqyeCfigeacBI0nvN jHWz/spzF3+4OS+3RJvoHtAQmProxyGib8iVsTxgZO3UUi4TSODeEt0i0kHSPY4sCciOyXfAyYoD DFqhRjOEwBBxhr+scU4C1T2AflozvDwq3VSONjrKJUkhd8+WsdXxMdPFgBQuiKKwUy11mz6KQfcR wmDehF3UaUoxa+YIhWPbKmycxuX/D8SvnqavzAeAL1OcRbEI/HsoroVlEFbBRNBZLJUlnTPs8ZcU 4+8rq5YX1GUrJL3jf6SAfSgO7UdkEET3PdcKFYtS+ruV1Cp5V0q4kCfI5jk25iiz8grM2wOzVSsc l1mEkhiEPH87HP0whhb544iioSnumd3HJKL7dzhRegsMizatupp8D65A2JziW0WKopa1iw9fti3A aBeNN4ijKZchBXHPgVx+YtWRHfcm4l8= OpenPGP: url=https://posteo.de/keys/markus.probst@posteo.de.asc; preference=encrypt These functions will be used to simply the serdev rust abstraction. It also contributes to the fixing of 2 race conditions in the serdev rust abstraction. Signed-off-by: Markus Probst --- drivers/tty/serdev/core.c | 44 ++++++++++++++++++++++++++++++++++++- drivers/tty/serdev/serdev-ttyport.c | 36 ++++++++++++++++++++++++++++++ include/linux/serdev.h | 6 +++++ 3 files changed, 85 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index 86d9cf8215ed..ca20304c7b20 100644 --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -193,6 +193,45 @@ void serdev_device_close(struct serdev_device *serdev) } EXPORT_SYMBOL_GPL(serdev_device_close); +/** + * serdev_device_pause_rx() - pause data receive + * @serdev: serdev device + * + * Pause calls to receive_buf. + * + * Note that if a call to receive_buf is currently executed, the function will + * sleep until it has finished. + */ +void serdev_device_pause_rx(struct serdev_device *serdev) +{ + struct serdev_controller *ctrl = serdev->ctrl; + + if (!ctrl || !ctrl->ops->pause_rx) + return; + + ctrl->ops->pause_rx(ctrl); +} +EXPORT_SYMBOL_GPL(serdev_device_pause_rx); + +/** + * serdev_device_resume_rx() - resume data receive + * @serdev: serdev device + * + * Resume calls to receive_buf. + * + * This can be called even if not paused to ensure data receive is active. + */ +void serdev_device_resume_rx(struct serdev_device *serdev) +{ + struct serdev_controller *ctrl = serdev->ctrl; + + if (!ctrl || !ctrl->ops->resume_rx) + return; + + ctrl->ops->resume_rx(ctrl); +} +EXPORT_SYMBOL_GPL(serdev_device_resume_rx); + static void devm_serdev_device_close(void *serdev) { serdev_device_close(serdev); @@ -404,6 +443,7 @@ EXPORT_SYMBOL_GPL(serdev_device_break_ctl); static int serdev_drv_probe(struct device *dev) { const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver); + struct serdev_device *sdev = to_serdev_device(dev); int ret; ret = dev_pm_domain_attach(dev, PD_FLAG_ATTACH_POWER_ON | @@ -411,7 +451,9 @@ static int serdev_drv_probe(struct device *dev) if (ret) return ret; - return sdrv->probe(to_serdev_device(dev)); + serdev_device_resume_rx(sdev); + + return sdrv->probe(sdev); } static void serdev_drv_remove(struct device *dev) diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c index 17c18d4b0cb8..6e1134976996 100644 --- a/drivers/tty/serdev/serdev-ttyport.c +++ b/drivers/tty/serdev/serdev-ttyport.c @@ -7,8 +7,10 @@ #include #include #include +#include "../tty.h" #define SERPORT_ACTIVE 1 +#define SERPORT_PAUSE_RX 2 struct serport { struct tty_port *port; @@ -36,6 +38,9 @@ static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp, if (!test_bit(SERPORT_ACTIVE, &serport->flags)) return 0; + if (test_bit(SERPORT_PAUSE_RX, &serport->flags)) + return 0; + ret = serdev_controller_receive_buf(ctrl, cp, count); dev_WARN_ONCE(&ctrl->dev, ret > count, @@ -185,6 +190,35 @@ static bool ttyport_close(struct serdev_controller *ctrl) return true; } +static void ttyport_pause_rx(struct serdev_controller *ctrl) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + + guard(mutex)(&serport->lock); + + scoped_guard(mutex, &serport->receive_lock) + set_bit(SERPORT_PAUSE_RX, &serport->flags); + + if (test_bit(SERPORT_ACTIVE, &serport->flags)) + tty_buffer_cancel_work(serport->tty->port); +} + +static void ttyport_resume_rx(struct serdev_controller *ctrl) +{ + struct serport *serport = serdev_controller_get_drvdata(ctrl); + + guard(mutex)(&serport->lock); + + if (!test_bit(SERPORT_PAUSE_RX, &serport->flags)) + return; + + scoped_guard(mutex, &serport->receive_lock) + clear_bit(SERPORT_PAUSE_RX, &serport->flags); + + if (test_bit(SERPORT_ACTIVE, &serport->flags)) + tty_buffer_restart_work(serport->tty->port); +} + static unsigned int ttyport_set_baudrate(struct serdev_controller *ctrl, unsigned int speed) { struct serport *serport = serdev_controller_get_drvdata(ctrl); @@ -289,6 +323,8 @@ static const struct serdev_controller_ops ctrl_ops = { .get_tiocm = ttyport_get_tiocm, .set_tiocm = ttyport_set_tiocm, .break_ctl = ttyport_break_ctl, + .pause_rx = ttyport_pause_rx, + .resume_rx = ttyport_resume_rx, }; struct device *serdev_tty_port_register(struct tty_port *port, diff --git a/include/linux/serdev.h b/include/linux/serdev.h index 0f4e81c0950d..02773554e759 100644 --- a/include/linux/serdev.h +++ b/include/linux/serdev.h @@ -89,6 +89,8 @@ struct serdev_controller_ops { int (*get_tiocm)(struct serdev_controller *); int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int); int (*break_ctl)(struct serdev_controller *ctrl, unsigned int break_state); + void (*pause_rx)(struct serdev_controller *ctrl); + void (*resume_rx)(struct serdev_controller *ctrl); }; /** @@ -194,6 +196,8 @@ static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctr int serdev_device_open(struct serdev_device *); void serdev_device_close(struct serdev_device *); int devm_serdev_device_open(struct device *, struct serdev_device *); +void serdev_device_pause_rx(struct serdev_device *serdev); +void serdev_device_resume_rx(struct serdev_device *serdev); unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int); void serdev_device_set_flow_control(struct serdev_device *, bool); int serdev_device_write_buf(struct serdev_device *, const u8 *, size_t); @@ -233,6 +237,8 @@ static inline int serdev_device_open(struct serdev_device *sdev) return -ENODEV; } static inline void serdev_device_close(struct serdev_device *sdev) {} +static inline void serdev_device_pause_rx(struct serdev_device *serdev) {} +static inline void serdev_device_resume_rx(struct serdev_device *serdev) {} static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev, unsigned int baudrate) { return 0; -- 2.56.1